Anthropogenic and biogenic winter sources of Arctic CO2 -: a model study

Long-range transport of anthropogenic and biogenic CO2 to a remote site in the Arctic is studied. A limited area, off-line, Eulerian atmospheric transport model is used, and the results are compared to the observed CO2 concentration at the "Ny-Alesund International Arctic Research and Monitoring Facility". Inventories of anthropogenic CO2 emissions and estimates of biogenic CO2 emissions are used to investigate the respective impact of these emissions on Arctic CO2 variations during 4 winter months. A direct comparison of the modelled and observed concentrations reveals remarkably good timing in the modelled variations as compared to the observed variations for most of the time. The correlation of observed versus modelled CO2 concentration is significant at the 95% confidence level. The biogenic and the anthropogenic CO2 emissions are shown to have approximately equal influence on Arctic CO2 variations during winter. Europe is found to be the dominant source of anthropogenic CO2 Lit the monitoring station, while Siberia and Northern America have little influence on Arctic CO2. during the months studied. These results contradict Engardt and Holmen whose results indicate that the lower-Ob region in western Siberia has a large impact on Arctic CO2.